similar to: compression via chattr

What happens if you set an individual file inside a subvolume as nocow (chattr +C) and then take a snapshot of that subvolume and modify the file in both? Will btrfs now ignore the nocow attribute completely or will it do "as few copies as possible"? (I''d love to know if it''s possible to visualize the fragmentation of a single file.) -- To unsubscribe from this list:

I just setup a new SSD with my laptop root filesystem, and at the time I though, "eh, I''ll just use zlib compression during the first copy, and then switch to lzo afterwards to maintain write speed when I''m using the laptop after the copy and reboot". Now, I rebooted with the new ssd and zlib compressed rootfs, and it seemed to boot slower than it did before with the

Hi, I planned to boost my btrfs performance today. here some errors I met: my ''btrfs filesystem show'' result: ~ # btrfs filesystem show failed to read /dev/sr0 Label: none uuid: 9b9aa9d9-760e-445c-a0ab-68e102d9f02e Total devices 1 FS bytes used 36.59GB devid 1 size 49.52GB used 49.52GB path /dev/sda6 Label: none uuid: 559dec06-4fd0-47c1-97b8-cc4fa6153fa0

We run a third party application that creates an inordinate amount of subdirectories in a single directory. To speed up I/O, I wanted to set the T attribute on the directory that will hold the subdirectories. The "chattr +T /usr/local/lepus-bb/a-0607" command returns status 0, but when I verify the setting, the attribute isn't there: # lsattr -d /usr/local/lepus-bb/a-0607

Hi all, as suggested on the mailing list I have converted the updated LZO code into git, so please pull my "lzo-update" branch from git://github.com/markus-oberhumer/linux.git lzo-update You can browse the branch at https://github.com/markus-oberhumer/linux/compare/lzo-update I''d ask some official kernel maintainer for review and to push this into linux-next so that it

Postfix <http://www.postfix.org> does a chattr +S on its spool directory when it is installed on Linux. This is what is written in the postfix startup script -- # # LINUX by default does not synchronously update directories - # that's dangerous for mail. # if [ -f /usr/bin/chattr ] then CHATTR="/usr/bin/chattr +S" else CHATTR=echo fi -- Is this still required on ext3 ?

Add the missing usage for No_COW since we''ve supported No_COW flag. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> --- misc/chattr.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/misc/chattr.c b/misc/chattr.c index 141ea6e..24254cc 100644 --- a/misc/chattr.c +++ b/misc/chattr.c @@ -83,7 +83,7 @@ static unsigned long sf; static void usage(void) {

Hello, is it possible to set nodatacow on a per-file basis? I couldn''t find anything. If not, wouldn''t that be a great feature to get around the performance issues with VM and database storage? Of course cloning should still cause COW. Thanks, Ralf-Peter -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to

We need such a sanity check for wrong start when we defrag a file, otherwise, even with a wrong start that''s larger than file size, we can end up changing not only inode''s force compress flag but also FS''s incompat flags. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- v2: make changelog more clearly. fs/btrfs/ioctl.c | 11 +++++++---- 1 files changed, 7

I want to eliminate the COW feature on all of my OS files. It is a nice feature for user files, but I don''t see a clear benefit for the actual OS files. And I suspect that COW induced fragmentation is causing or aggravating problems with my system including the boot open_ctree problem. I had planned to recursively chattr these files to "nodatacow" status but then I ran

- Add incompat flag, otherwise btrfs-progs will report error when operating on btrfs filesystems mounted with lzo option. - Allow to turn on lzo compression for defrag operation: # btrfs filesystem defragment -c[zlib, lzo] <file> Note: "-c zlib" will fail, because that''s how getopt() works for optional arguments. Signed-off-by: Li Zefan

Add the missing usage for No_COW since we''ve supported No_COW flag. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> --- v1->v2: sort options alphabetically, thanks to Roman Mamedov. misc/chattr.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/misc/chattr.c b/misc/chattr.c index 141ea6e..24254cc 100644 --- a/misc/chattr.c +++ b/misc/chattr.c @@ -83,7

Hi list, I just noticed in the chattr(1) man page that there exists a 'j' attribute which actually does the same thing that data=journal mount option would do, expect it only sets this property on the directories of my choice. Big Thanks to the one that came up with that idea :) It allows me to set +j on mail queues that must sit on the same partitions as the rest of the system (the guy

In support of the recently added capability to remount with lzo compression, provide a helper function to check the compression INCOMPAT flags when remounting with lzo compression, and set the flags if necessary. Also, implement the new helper function when defragmenting with explicit lzo compression and when setting the default subvolume. Signed-off-by: Mitch Harder

Is this useful to anyone? Got this after a crash/reboot: if (block_rsv) { WARN_ON(block_rsv->size > 0); <<<<<<<<<<<<<<<<<<<<<< btrfs_free_block_rsv(root, block_rsv); } ------------[ cut here ]------------ WARNING: at fs/btrfs/inode.c:2165 btrfs_orphan_commit_root+0xcb/0xdf() Hardware name: 2429A78 Modules linked in:

I''ve been working on running down intermittent ENOSPC issues. I can only seem to replicate ENOSPC errors when running zlib compression. However, I have been seeing similar ENOSPC errors to a lesser extent when playing with the LZ4HC patches. I apologize for not following up on this sooner, but I had drifted away from using zlib, and didn''t notice there was still an issue. My

Hi, so here it is, LZ4 compression method inside btrfs. The patchset is based on top of current Chris'' for-linus + Andi''s snappy implementation + the fixes from Li Zefan. Passes xfstests and stresstests. I haven''t measured performance on wide range of hardware or workloads, rather wanted to publish the patches before I get distracted again. I''d like to ask

Hello, Darik Horn sent a pull request adding support for LZ4. LZ4 is supposed to be a very fast compression algorithm, especially when it comes to decompression. I did a quick benchmark with zlib, LZO and LZ4. Now, there are many benchmarks you can find online, but most of them deal with compressing large files. Tinc on the other hand has to compress small packets individually. So I did the

I converted an ext4 filesystem with btrfs-convert, mounted it, and wanted to do "lzop -d ...". The result was an immediate Oops (btrfs is on LVM, on dm-crypt, on /dev/sdb which is USB-connected). mini-904.img.lzo dentry_open failed BUG: unable to handle kernel paging request at ffffffcd IP: [<c01b5f36>] fput+0x6/0x30 *pde = 00575067 *pte = 00000000 Oops: 0002 [#1] SMP last sysfs

Hi! The problem is that the BTRFS raid10 filesystem without any understandable cause refuses to mount. Here is dmesg output: [77847.845540] device label linux-btrfs-raid10 devid 3 transid 45639 /dev/sdc1 [77848.633912] btrfs: allowing degraded mounts [77848.633917] btrfs: enabling auto defrag [77848.633919] btrfs: use lzo compression [77848.633922] btrfs: turning on flush-on-commit [77848.658879]